Effect of graphene surface properties on mechanical properties and microstructure of cement mortar composites
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摘要: 近年来，利用石墨烯及其衍生物改善水泥基复合材料性能受到了广泛关注。但是，关于石墨烯表面性质对水泥基材料的性能影响却鲜有报道。为此，采用不同浓度的L-抗坏血酸(10wt%、20wt%、30wt%、50wt%和70wt%)和还原时间(15 min、30 min、45 min和60 min)将氧化石墨烯(GO)转化为还原氧化石墨烯(rGO)，然后以相同剂量(水泥质量的0.05%)加入到水泥砂浆复合材料中，研究了不同还原程度的rGO对水泥砂浆力学性能的影响。测试结果表明，通过50wt%L-抗坏血酸还原30 min制备的rGO的加入使水泥砂浆28天抗压强度和抗折强度相比于普通试样分别提高了36.84%和43.24%。SEM等分析表明，GO和不同还原程度的rGO均可促进Ca(OH)2的结晶和水化硅酸钙凝胶(C-S-H)中二氧化硅四面体的形成，形成致密的微观结构。但存在一个最佳阈值(即通过50wt%的L-抗坏血酸还原30 min)，在该阈值下，有利于rGO表面官能团与水化产物的结合。Abstract: In recent years, the use of graphene and its derivatives to improve the properties of cementitious composites have received much attention. However, there are few reports on the effect of graphene surface properties on the performance of cement-based materials. Graphene oxide (GO) was converted to reduced graphene oxide (rGO) using different concentrations of L-ascorbic acid (10wt%, 20wt%, 30wt%, 50wt% and 70wt%) and reduction time (15 min, 30 min, 45 min and 60 min) which was then added to the cement mortar composites at the same dosing level 0.05% (by weight cement). The effects of different degrees of reduced rGO on the mechanical properties of cement mortar were investigated. The test results show that the incorporation of rGO prepared by 50wt% L-ascorbic acid reduction 30 min increases the 28 days compressive strength and flexural strength of cement mortar by 36.84% and 43.24%, respectively, compared to the normal specimens. SEM and other analyses show that both GO and rGO with different degrees of reduction could promote the crystallization of Ca(OH)2 and the formation of silica tetrahedra in hydrated calcium silicate gels (C-S-H) to form dense microstructures. However, an optimal threshold exists (i.e., 30 min reduction by 50wt% L-ascorbic acid). At this threshold, the binding of rGO surface functional groups to hydration products is favored.
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Key words:
- graphene oxide /
- reduced graphene oxide /
- mechanical properties /
- hydration products /
- microstructure
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图 1 GO (a) 和还原氧化石墨烯(rGO) (b) 表面微观形貌
Figure 1. Surface micromorphologies of GO (a) and reduce graphene oxide (rGO) (b)
图 3 GO和不同还原条件下rGO的Zeta(ζ)电位绝对值：(a) 固定还原时间(30 min)、不同L-AA浓度(10wt%~70wt%)；(b) 固定L-AA浓度(50wt%)、不同还原时间(15~60 min)
Figure 3. Absolute values of Zeta (ζ)-potential for GO and rGO with different reduction conditions: (a) Fixed reduction time (30 min), different L-AA concentrations (10wt%-70wt%); (b) Fixed L-AA concentration (50wt%), different reduction time (15-60 min)
In rGO/x-y, x—L-AA concentration; y—Reduction time
图 4 不同还原条件对rGO/水泥砂浆抗折强度的影响：(a) 固定还原时间30 min、不同L-AA浓度(10wt%~70wt%)；(b)固定L-AA浓度为50wt%、不同还原时间(15~60 min)
Figure 4. Effect of different reduction conditions on flexural strength of rGO/cement mortar: (a) Fixed 30 min reduction time, different concentrations of L-AA (10wt%-70wt%); (b) Fixed L-AA concentration of 50wt%, different reduction time (15-60 min)
图 5 不同还原条件对 rGO/水泥砂浆抗压强度的影响：(a) 固定还原时间30 min, 不同L-AA浓度(10wt%~70wt%)；(b) 固定L-AA浓度为50wt%，不同还原时间(15~60 min)
Figure 5. Effect of different reduction conditions on compressive strength of rGO/cement mortar: (a) Fixed 30 min reduction time, different concentrations of L-AA (10wt%-70wt%); (b) Fixed L-AA concentration of 50wt%, different reduction time (15-60 min)
图 6 不同还原条件对rGO/水泥砂浆吸水量的影响：(a) 固定还原时间30 min、不同L-AA浓度(10wt%~70wt%)；(b) 固定L-AA浓度为50wt%、不同还原时间(15~60 min)
Figure 6. Effect of different reduction conditions on water absorption of rGO/cement mortar: (a) Fixed 30 min reduction time, different concentrations of L-AA (10wt%-70wt%); (b) Fixed L-AA concentration of 50wt%, different reduction time (15-60 min)
图 7 参比样品R和rGO/0.5CM-30的毛细管吸水系数线性拟合曲线：(a) 初始吸水拟合曲线；(b) 二次吸水拟合曲线
Figure 7. Linear fitting curves of capillary water absorption coefficients of the reference sample and rGO/0.5CM-30: (a) Initial absorption fitting curves; (b) Secondary absorption fitting curves
图 8 添加GO和rGO的水泥砂浆在28天时的XRD图谱：(a) 固定还原时间30 min，不同L-AA浓度(10wt%~70wt%)；(b) 固定L-AA浓度为50wt%，不同还原时间(15~60 min)
Figure 8. XRD patterns of cement mortars with GO and rGO added at 28 days: (a) Fixed 30 min reduction time, different concentrations of L-AA (10wt%-70wt%); (b) Fixed L-AA concentration of 50wt%, different reduction time (15-60 min)
C-S-H—Calcium silicate hydrate
图 9 GO和rGO的水泥砂浆在28天时的TG/DTG曲线
Figure 9. TG/DTG curves of cement mortars with GO and rGO added at 28 days
图 10 28天时水泥砂浆样品的SEM图像：(a) R；(b) 含0.05wt%的GO；((c)、(d)) 含0.05wt%的rGO
Figure 10. SEM images of cement mortar samples at 28 days: (a) R; (b) With 0.05wt% of GO; ((c), (d)) With 0.05wt% of rGO
AFt—Ettringite
表 1 PO 42.5水泥化学组成
Table 1. Chemical composition of PO 42.5 cement
wt% CaO SiO2 Al2O3 Fe2O3 SO3 MgO Na2O 61.14 22.64 5.18 2.14 2.04 2.22 0.67 
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表 2 PO 42.5水泥物理性能
Table 2. Physical performance of PO 42.5 cement
Ignition loss/% Initial setting time/min Final setting time/h Specific surface area/
(m2·kg−1)Flexural strength/MPa Compressive strength/MPa 3 days 28 days 3 days 28 days ≤ 5 180 6 351 6.0 8.4 30.4 53.6
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表 3 氧化石墨烯(GO)中L-抗坏血酸(L-AA)用量
Table 3. Amount of L-ascorbic acid (L-AA) used in graphene oxide (GO)
No. Mass fraction of
GO/wt%L-AA
concentration/(mg·mL−1)Reaction time/min 1 10 0.11 30 2 20 0.21 30 3 30 0.325 30 4 50 0.54 30 5 70 0.75 30 6 50 0.54 15 7 50 0.54 30 8 50 0.54 45 9 50 0.54 60
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表 4 水泥砂浆配合比
Table 4. Mix proportion of cement mortar composites
Sample Cement/g Water/g Sand/g GO or rGO/g NS/g R 100 48 200 0 0.2 GO/CM 100 48 200 0.05 0.2 rGO/0.1CM-30 100 48 200 0.05 0.2 rGO/0.2CM-30 100 48 200 0.05 0.2 rGO/0.3CM-30 100 48 200 0.05 0.2 rGO/0.5CM-30 100 48 200 0.05 0.2 rGO/0.7CM-30 100 48 200 0.05 0.2 rGO/0.5CM-15 100 48 200 0.05 0.2 rGO/0.5CM-30 100 48 200 0.05 0.2 rGO/0.5CM-45 100 48 200 0.05 0.2 rGO/0.5CM-60 100 48 200 0.05 0.2 Notes: rGO—Reduce graphene oxide; NS—Naphthalene superplasticizer; CM—Cement mortar; R—Blank sample group; GO/CM—Add 0.05wt%GO cement mortar sample group; rGO/0.1CM-30—Add 0.05wt%rGO (by 10wt% L-ascorbic acid reduction 30 min) cement mortar sample group; rGO/0.5CM-15—Add 0.05wt%rGO (by 50wt% L-ascorbic acid reduction 15 min) cement mortar sample group.
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表 5 rGO水泥砂浆试样rGO/0.5CM-30的水化产物元素组成
Table 5. Elemental composition of hydration products of rGO cement mortar sample rGO/0.5CM-30
wt% Crystal shape C O Ca Mg Al Si S K Fe Needle-like product 1.12 41.14 35.48 1.57 2.62 9.33 3.20 2.66 2.87 Lamella product 3.60 44.19 34.86 0.90 1.61 8.92 2.56 2.16 1.20 Amorphous product 3.24 43.39 35.77 1.06 1.60 8.87 2.90 1.52 1.65 Rodlike product 3.01 46.02 35.61 1.27 1.29 8.12 2.39 1.46 0.82
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[1] 程志海, 杨森, 袁小亚. 石墨烯及其衍生物掺配水泥基材料研究进展[J]. 复合材料学报, 2021, 38(2):339-360.CHENG Zhihai, YANG Sen, YUAN Xiaoya. Research progress of cement-based materials blended with graphene and its derivatives[J]. Acta Materiae Compositae Sinica,2021,38(2):339-360(in Chinese). [2] 杨一凡, 何智海, 詹培敏. 石墨烯及其衍生物在水泥基材料中的应用与研究进展[J]. 硅酸盐通报, 2020, 39(3):669-676.YANG Yifan, HE Zhihai, ZHAN Peimin. Application and research progress of graphene and its ramifications in cementitious materials[J]. Bulletin of the Chinese Ceramic Society,2020,39(3):669-676(in Chinese). [3] 梁兴文, 胡翱翔, 于婧等. 钢纤维对超高性能混凝土抗弯力学性能的影响[J]. 复合材料学报, 2018, 35(3):722-731.LIANG Xingwen, HU Aoxiang, YU Jing, et al. Effect of steel fibers on the flexural response of ultra-high performance concrete[J]. Acta Materiae Compositae Sinica,2018,35(3):722-731(in Chinese). [4] NGUYEN W, DUNCN J F, JEN G, et al. Influence of matrix cracking and hybrid fiber reinforcement on the corrosion initiation and propagation behaviors of reinforced concrete[J]. Corrosion Science,2018,140:168-181. doi: 10.1016/j.corsci.2018.06.004 [5] YOO D Y, BANTHIA N, FUJIKAKE K, et al. Fiber-reinforced cement composites: Mechanical properties and structural implications 2019[J]. Advances in Materials Science and Engineering,2019,2019:1-2. [6] WANG B, ZHAO R, ZHANG T. Pore structure and durability of cement-based composites doped with graphene nanoplatelets[J]. Materials Express,2018,8(2):149-156. doi: 10.1166/mex.2018.1421 [7] NOVOSELOV K S, GEIM A K, MOROZOV S V, et al. Electric field effect in atomically thin carbon films[J]. Science,2004,306(5696):666-669. doi: 10.1126/science.1102896 [8] WANG B, JIANG R, WU Z. Investigation of the mechanical properties and microstructure of graphene nanoplatelet-cement composite[J]. Nanomaterials,2016,6(11):200. doi: 10.3390/nano6110200 [9] LIU J, FU J, YANG Y, et al. Study on dispersion, mechanical and microstructure properties of cement paste incorporating graphene sheets[J]. Construction and Building Materials,2019,199:1-11. doi: 10.1016/j.conbuildmat.2018.12.006 [10] DU H, DAI P S. Enhancement of barrier properties of cement mortar with graphene nanoplatelet[J]. Cement and Concrete Research,2015,76:10-19. doi: 10.1016/j.cemconres.2015.05.007 [11] KRYSTEK M, CIESIELSKI A, SAMMORÌ P. Graphene-based cementitious composites: Toward next-generation construction technologies[J]. Advanced Functional Materials,2021,31(27):2101887. [12] 王悦, 王琴, 郑海宇, 等. 分散剂对石墨烯水泥基复合材料压敏性能的影响研究[J]. 硅酸盐通报, 2021, 40(8):2515-2526.WANG Yue, WANG Qin, ZHENG Haiyu, et al. Influence of dispersant on pressure-sensitive properties of graphene cement-based composites[J]. Bulletin of the Chinese Ceramic Society,2021,40(8):2515-2526(in Chinese). [13] ZHAO L, GUO X, SONG L, et al. An intensive review on the role of graphene oxide in cement-based materials[J]. Construction and Building Materials,2020,241:117939. doi: 10.1016/j.conbuildmat.2019.117939 [14] LI X, LIU Y M, LI W G, et al. Effects of graphene oxide agglomerates on workability, hydration, microstructure and compressive strength of cement paste[J]. Construction and Building Materials,2017,145:402-410. doi: 10.1016/j.conbuildmat.2017.04.058 [15] SHARMA S, SUSAN D, KOTHIYAL N C, et al. Graphene oxide prepared from mechanically milled graphite: Effect on strength of novel fly-ash based cementitious matrix[J]. Construction and Building Materials,2018,177:10-22. doi: 10.1016/j.conbuildmat.2018.05.051 [16] MOHAMMED A, SANJAYAN J G, DUAN W H, et al. Graphene oxide impact on hardened cement expressed in enhanced freeze-thaw resistance[J]. Journal of Materials in Civil Engineering,2016,28(9):04016072. doi: 10.1061/(ASCE)MT.1943-5533.0001586 [17] 徐凯丽. 石墨烯-水泥基复合材料的制备及其功能性研究[D]. 南京: 东南大学, 2018.XU Kaili. Preparation and functional study of graphene cement composite[D]. Nanjing: Southeast University, 2018(in Chinese). [18] PRABAVATHY S, JEYASUBRAMANIAN K, PRASANTH S, et al. Enhancement in behavioral properties of cement mortar cubes admixed with reduced graphene oxide[J]. Jour-nal of Building Engineering,2020,28:101082. doi: 10.1016/j.jobe.2019.101082 [19] MURUGAN M, SANTHANAM M, GUPTA S S, et al. Influence of 2D rGO nanosheets on the properties of OPC paste[J]. Cement and Concrete Composites,2016,70:48-59. doi: 10.1016/j.cemconcomp.2016.03.005 [20] GHOLAMPOUR A, VALIZADEH K M, TRAN D N H, et al. From graphene oxide to reduced graphene oxide: Impact on the physiochemical and mechanical properties of graphene-cement composites[J]. ACS Applied Materials & Interfaces,2017,9(49):43275-43286. [21] GAO J, LIU F, LIU Y, et al. Environment-friendly method to produce graphene that employs vitamin C and amino acid[J]. Chemistry of Materials,2010,22(7):2213-2218. doi: 10.1021/cm902635j [22] 彭晖, 戈娅萍, 杨振天, 等. 氧化石墨烯增强水泥基复合材料的力学性能及微观结构[J]. 复合材料学报, 2018, 35(8):2132-2139.PENG Hui, GE Yaping, YANG Zhentian, et al. Mechanical properties and microstructure of graphene oxide reinforced cement-based composite[J]. Acta Materiae Compositae Sinica,2018,35(8):2132-2139(in Chinese). [23] FERNÁNDEZ-MERINO M J, GUARDIA L, PAREDES J I, et al. Vitamin C is an ideal substitute for hydrazine in the reduction of graphene oxide suspensions[J]. The Journal of Physical Chemistry C,2010,114(14):6426-6432. doi: 10.1021/jp100603h [24] 何威, 许吉航, 焦志男. 少层石墨烯对水泥净浆流动性能及力学性能的影响[J]. 复合材料学报, 2022, 39(11):5637-5649.HE Wei, XU Jihang, JIAO Zhinan. Effect of few-layer graphene on the fluidity and mechanical properties of cement paste[J]. Acta Materiae Compositae Sinica,2022,39(11):5637-5649(in Chinese). [25] WANG Y, YA J, OUYANG D. Effect of graphene oxide on mechanical properties of cement mortar and its strengthening mechanism[J]. Materials,2019,12(22):3753. doi: 10.3390/ma12223753 [26] 国家质量技术监督局. 水泥胶砂强度检验方法 (ISO法): GB/T 17671—1999[S]. 北京: 中国标准出版社, 1999.The State Bureau of Quality and Technical Supervision. Testing method of cement mortar strength (ISO method): GB/T 17671—1999[S]. Beijing: China Standards Press, 1999(in Chinese). [27] MUTHU M, YANG E H, UNLUER C. Resistance of graphene oxide-modified cement pastes to hydrochloric acid attack[J]. Construction and Building Materials,2021,273:121990. doi: 10.1016/j.conbuildmat.2020.121990 [28] MEYER J C, GEIM A K, KATSNELAON M I, et al. The structure of suspended graphene sheets[J]. Nature,2007,446(7131):60-63. doi: 10.1038/nature05545 [29] KWON M, YANG J, KIM H, et al. Controlling graphene wrinkles through the phase transition of a polymer with a low critical solution temperature[J]. Macromolecular Rapid Communications,2021,42(23):2100489. doi: 10.1002/marc.202100489 [30] SAMARI-KERMANI M, JAFARI S, RAHNAMA M, et al. Ionic strength and zeta potential effects on colloid transport and retention processes[J]. Colloid and Interface Science Communications,2021,42:100389. doi: 10.1016/j.colcom.2021.100389 [31] ALKHATEB H, Al-OSTAZ A, CHENG A H D, et al. Materials genome for graphene-cement nanocomposites[J]. Journal of Nanomechanics and Micromechanics,2013,3(3):67-77. doi: 10.1061/(ASCE)NM.2153-5477.0000055 [32] LI X, LU Z, CHUAH S, et al. Effects of graphene oxide aggregates on hydration degree, sorptivity, and tensile splitting strength of cement paste[J]. Composites Part A: Applied Science and Manufacturing,2017,100:1-8. doi: 10.1016/j.compositesa.2017.05.002 [33] KRYSTEK M, PAKULSKI D, GÓRSKI M, et al. Electrochemically exfoliated graphene for high-durability cement composites[J]. ACS Applied Materials & Interfaces,2021,13(19):23000-23010. [34] WANG B, DENG S. Effect of graphene nanoplatelets on the properties, pore structure and microstructure of cement composites[J]. Materials Express,2018,8(5):407-416. doi: 10.1166/mex.2018.1447 [35] YASEEN S A, YISEEN G A, LI Z. Elucidation of calcite structure of calcium carbonate formation based on hydrated cement mixed with graphene oxide and reduced graphene oxide[J]. ACS Omega,2019,4(6):10160-10170. doi: 10.1021/acsomega.9b00042 [36] MENG S, OUYANGU X, FU J, et al. The role of graphene/graphene oxide in cement hydration[J]. Nanotechnology Reviews,2021,10(1):768-778. doi: 10.1515/ntrev-2021-0055 [37] 吕生华, 张佳, 朱琳琳, 等. 氧化石墨烯对水泥基复合材料微观结构的调控作用及对抗压抗折强度的影响[J]. 化工学报, 2017, 68(6):2585-2595.LV Shenghua, ZHANG Jia, ZHU Linlin, et al. Regulation of graphene oxide on microstructure of cement composites and its impact on compressive and flexural strength[J]. CIESC Journal,2017,68(6):2585-2595(in Chinese). [38] WANG B M, DENG S. Effect and mechanism of graphene nanoplatelets on hydration reaction, mechanical properties and microstructure of cement composites[J]. Construction and Building Materials,2019,228:116720. doi: 10.1016/j.conbuildmat.2019.116720 [39] DEVI S C, KHAN R A. Effect of graphene oxide on mechanical and durability performance of concrete[J]. Journal of Building Engineering,2020,27:101007. doi: 10.1016/j.jobe.2019.101007 [40] KRYSTEK M, PAKULAKI D, PATRONIAK V, et al. High-performance graphene-based cementitious composites[J]. Advanced Science,2019,6(9):1801195. doi: 10.1002/advs.201801195 [41] QURESHI T S, PANESAR D K. Impact of graphene oxide and highly reduced graphene oxide on cement-based composites[J]. Construction and Building Materials,2019,206:71-83. doi: 10.1016/j.conbuildmat.2019.01.176 -
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